CN111733419A

CN111733419A - Acidic etching solution and device and method for recycling electrolytic copper extraction

Info

Publication number: CN111733419A
Application number: CN202010778994.5A
Authority: CN
Inventors: 徐麟; 杨代军; 黄勇
Original assignee: Shanghai Elo Technology Co ltd
Current assignee: Shanghai Elo Technology Co ltd
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2020-10-02

Abstract

The invention provides an acidic etching solution, and an electrolytic copper extraction recycling device and method thereof, which have excellent etching stability, etching speed and fineness, have a simple controllable in-situ electrolysis recycling mode, obtain a smooth and bright copper plate, have no expansion of the etching solution, generate no chlorine gas, do not need a preparation cylinder to perform manual intervention and adjustment, and can directly etch back an etching line of an etching machine with the recycling solution for production.

Description

Acidic etching solution and device and method for recycling electrolytic copper extraction

Technical Field

The invention belongs to the field of circuit board acid etching, and particularly relates to an acid etching solution, and a device and a method for recycling electrolytic copper extraction of the acid etching solution.

Background

The circuit acid etching manufacturing process of the circuit board is a process of etching (oxidation reduction reaction) copper foil on a copper-clad plate by adopting multi-component acid etching sub-solution rich in hydrochloric acid, sodium chloride, sodium chlorate, ammonium chloride and the like to form a circuit, and meanwhile, the generated copper-containing acid etching waste solution is complex in components rich in copper chloride, hydrochloric acid, sodium chloride and ammonium chloride. The traditional acid etching process uses a single-liquid acid sub-liquid process comprising the steps of using 31% hydrochloric acid as the sub-liquid, oxidizing and regenerating the air, using 15% hydrochloric acid, 100g/L ammonium chloride, an organic additive complexing agent and the like to perform acid etching, and because the two acid etching processes have high acidity, waste liquid ammonia nitrogen is difficult to treat, and the defects that the content of monovalent copper is high, the two acid etching processes cannot be used for precise line etching and the like are gradually eliminated. At present, three materials of 31 percent hydrochloric acid, an oxidant (hydrogen peroxide, sodium hypochlorite or sodium chlorate aqueous solution) and water are generally adopted as sub-solutions to be added independently, three parameters of copper chloride online detection and automatic addition regeneration controller ECS9100 produced by Japan Aqua company or Shanghai Yilan company are used for respectively reflecting the acidity of 2.0mol/L, the copper ion concentration of 140g/L and the monovalent copper ion concentration of 2g/L (the lower the ORP value is, the higher the monovalent copper content is, the weaker the oxidative etching capability of the liquid medicine is, when the monovalent copper concentration exceeds 2g/L, burrs and incomplete etching are easy to occur in circuit etching, the problems of slow etching speed and the like affect the quality and the capacity of the circuit board), when the acidity is lower than a set value, the hydrochloric acid is added automatically, the specific gravity is higher than the set value, the water is automatically supplemented, the ORP is lower than the set value, the oxidant is automatically supplemented, and finally, the stable acid etching working solution (also called acid etching mother solution) is formed, the component composition of the stable acid etching working solution is generally 1.0-3.0mol/L H +, 160g/L divalent copper of 120 ion, 1-3g/L monovalent copper, 330g/L chloride ion of 230 ion, and the rest water. And with the continuous replenishment of the sub-solution, the acidic etching mother solution overflows out of the etching machine to the etching waste solution storage barrel to be stored as the copper-containing acidic etching waste solution.

The copper in the copper-containing acidic etching waste liquid can be removed by chemical or physical reaction methods such as an acidic neutralization precipitation method, a displacement reduction method, distillation, electrolysis and the like, so that the components of the etching liquid are damaged, and the tail liquid after copper removal needs further environmental-friendly physical or chemical treatment, cannot be recycled, and causes great environmental-friendly disposal cost and resource waste. For example, in the patent, CN201910751200.3, a Limited company for comprehensive utilization of hazardous waste in oasis, Anhui, and a preparation method thereof, electrolysis and sodium hydroxide neutralization are adopted to prepare copper hydroxide; a method for producing ferrous chloride by replacing acid etching solution of Shaanxi Xin kinescope circulating treatment application company CN 201910584325.1; hongboard (Jiangxi) Inc. CN201410088652.5 introduced a method for obtaining sponge copper and preparing poly-ferric chloride by iron-aluminum substitution; a regeneration method of acidic etching solution, Guangdong Germany and environmental protection science and technology company, CN201910473571.X, introduces a method for obtaining a copper chloride crystallization by-product by adding an oxidant and decompressing and evaporating; shenzhen, Xinruisi environmental protection science and technology Limited CN201710456226.6 introduces a method for preparing copper sulfate by adding sulfuric acid; CN201811002050.8, rumin, environmental protection technologies ltd, luzhou, da bay hundred million fields; plum dawn clear; liu jade CN201710665696.3 introduces a method for obtaining copper hydroxide mud by an acid-base neutralization chemical precipitation method; CN201710321291.8, a fine chemical industry Co., Ltd, Xiang , Peruo county, Guangdong province, introduces a chemical treatment method, in which after acid-base etching waste liquid is neutralized to generate basic copper chloride, the basic copper chloride is reacted with an alkaline solution to form copper oxide, and then the copper oxide is reacted with concentrated sulfuric acid to generate copper sulfate; CN201810040730.2 of Baikun materials Limited, Zhang hong City introduces a process method of evaporation, reverse osmosis and electrolytic copper extraction, and CN201611161135.1 of Ganzhouming Ganggao scientific and technological Co., Ltd introduces a method of distillation collection of hydrochloric acid, crystallization removal of sodium chloride and electrolytic copper extraction; the Shanxi Rui Kai environmental protection science and technology Limited CN201510284808.1 introduces a method for acid-base neutralization precipitation, sulfuric acid acidification and exudation and electrodeposition copper extraction; the Xianrui Kai electric power science and technology Co., Ltd CN201310038564.X introduces a method for collecting hydrochloric acid by distillation, neutralizing, precipitating, acidifying with sulfuric acid and electrolytically extracting copper, and the Changsha platinum shark environmental protection equipment Co., Ltd CN201210477021.3 introduces a method for obtaining copper chloride by adding oxidant to regenerate and crystallize; the Hangzhou electronic science and technology university CN201320581155.X introduces a processing device for centrifugal separation and crystallization. The method mentioned in the patent successfully extracts the copper in the acid etching solution, but the formed copper-removing tail solution needs environmental-friendly advanced treatment or resource utilization and can not be etched back for cyclic utilization.

The current patent mentions that copper is extracted by using etching solution to obtain a copper plate, and the etching solution after copper extraction is recycled. In the whole process of electrolytic copper extraction by the acidic etching solution, cathode copper ions become monovalent copper ions and finally become metal copper to be sucked out. The chlorine ions in the anode area are changed into chlorine gas to be separated out, and a large amount of chlorine gas is formed and needs to be absorbed by adopting jet flow, or by reducing substances such as ferrous chloride or alkali. Such as Huang slim Xiang CN201910874769.9, Shanghai Ba Ling environmental protection technology Co., Ltd CN201910892863.7, CN201510543893.9, CN201520664904.4, CN201520664905.9, CN201520664901.0, CN201910859208.1, Shenzhen Qin Tian Zhengyuan environmental protection technology Co., Ltd CN201910383686.X CN201820344289.2CN201820329771.9CN201610732257.5, Shenzhong yi Yuancheng environmental protection technology Co., Ltd CN201910440179.5CN201910434545.6CN201920750589.5CN201920759934.1, Guanzhou Guichi environmental protection technology Co., CN201711453601.8CN201711453595.6, Huzhou Zhengding environmental protection technology Co., Ltd CN201910318744.0, Guangzhou Shenya New environmental protection technology Co., Ltd CN201910034249.7CN201810972330.5CN201920059755.7CN201920059753.8CN201920059666.2CN201920059766.5 Jiangsu Jingsu environmental protection technology Co., Ltd CN201810682763.7CN201620094215.9CN201821003989.1, Shenzhou Jingyan Shenchi scientific technology Co., Ltd CN201711038350.7CN201521080212.1CN201520470313.3CN201721402660.8, Suzhou Mei Yuyan environmental protection technology Co., Ltd CN201510028257.2, Kunjin Shenshan environmental protection technology development Co., Ltd 201210023805.9, He Wu CN201821705805.6, Shenzhou Jie environmental protection technology Co., Ltd CN201720533072.1, CN 58 201720333340.5, CN 58573 Shenzhou environmental protection technology Co., CN 118573 Shenzhou environmental protection technology Co., CN 11824, leaf construction CN200520067901.9 mentions a similar approach. Shenzhen Jiichi science and technology Limited CN201510970148.2 adopts a three-dimensional structure consisting of a main anode and a partial anode to effectively inhibit chlorine gas from being separated out, but the generation of chlorine gas cannot be completely avoided. The chlorine is dangerous, leakage easily causes suffocation, and simultaneously, ferrous chloride can generate a large amount of ferric trichloride waste liquid after absorbing the chlorine, thereby bringing great load to subsequent environment-friendly water treatment. In addition, chloride ions are changed into chlorine to be separated out, so that a production line needs to supplement a large amount of hydrochloric acid or sodium chloride to supplement the chloride ions, the acidic etching waste liquid expands after the acidic etching liquid is recycled, the reuse rate of the etching liquid is only 40-60%, and the full recycling of the acidic etching liquid cannot be realized.

In order to improve the danger problem of chlorine gas precipitation, patents propose that sulfuric acid is used as anolyte, copper plates are extracted by methods such as extraction or iron anode, oxygen or ferrous chloride flocculant is generated at the anode, such as Chengdong Hua environmental protection science and technology corporation CN201910002195.6, CN201420852820.9, CN201220423809.1, CN201220423803.4, CN201220423840.5, CN201220423519.7, CN201620854970.2, Shenzhen Shentaihui Chun limited CN201710310370.9, Nanjing environmental protection science and technology corporation CN201810707506.4, Guangzhou Hei environmental protection science and technology corporation CN201710301200.4 Kutler environmental protection science and technology (Suzhou) limited CN010751859.CN201410001343.20141530.8CN201420001975.1CN201401658.X, Heizhou Yihui Yuanrong Baoji CN200910214606.4 adopts cation membrane electrolysis, cathode region is acid etching waste liquid, and dilute sulfuric acid is used in anode region. The copper plate and dilute hydrochloric acid obtained by cathodic electrolysis can be returned to the acid etching production line to be used as hydrochloric acid additive, and oxygen is generated by anodic electrolysis, so that the monovalent copper in the etching waste liquid is oxidized by nascent oxygen. Sulfuric acid and copper sulfate are added into a cathode area of Guangzhou city Tian Yi chemical company CN201110257975.9, the concentration of the sulfuric acid is controlled to be 5-15% by volume, and the concentration of copper ions is controlled to be 20-80 g/l; CN201810753588.6, environmental protection science and technology Limited of Zhengding in Huizhou city, introduces a method for extracting copper by electrolysis by using acidic etching waste liquid and copper sulfate solution as cathode and anode solutions. Shenzhen, Xinruisi environmental protection science and technology Limited CN201710455878.8 introduces a copper extraction process method of diffusion dialysis, extraction and electrolysis. Subi cloud CN201710190837.0 introduces a method for preparing a polyferric chloride flocculant by taking iron as an anode and obtaining a copper plate at a cathode, and obtaining a ferrous chloride solution at the anode; menghui CN201310231008.4CN201210438732.X introduces a copper extraction method by a diaphragm electrolysis and extraction composite process; the Guangzhou Jichi environmental protection science and technology limited company CN201110252985.3CN201120321551.X introduces a method for obtaining copper powder by electrolysis and separation by a separator, wherein cathode copper ions are changed into copper powder, and anode monovalent copper is changed into bivalent copper; the environmental protection science and technology company CN201420588458.9, Chongqing Kangpu chemical industry company CN201210361521.0, introduced a method for extracting copper from acidic etching solution by extraction and electrolysis. The tail liquid after copper extraction in the method is supplemented to the etching line as hydrochloric acid for continuous recycling, but the oxygen of the anode cannot completely oxidize monovalent copper in the etching working solution, so that the etching production line needs to supplement a large amount of oxidant to generate acid etching solution expansion, needs to be disposed outside, and cannot be fully recycled. In addition, if the ion membrane is broken, sulfate radicals are mixed into the etching solution, which affects the etching rate and etching quality. The extraction method needs alkali pre-adjustment to improve the pH value, and a large amount of extraction rinsing liquid is generated, so that environmental-friendly advanced treatment or resource utilization is needed.

In order to solve the problems, the patent proposes that an ion membrane copper extraction device and an etching machine are adopted to carry out online copper extraction and ORP530-550 control method. The cathode extracts the copper plate, the anolyte and the acid etching working solution of the etching machine circulate on line, ORP control is identical to 530-550mV of the etching production line, monovalent copper is provided by the etching circuit board of the etching machine, so that the reaction of the anode area of the copper extraction equipment is changed from chlorine ion into chlorine gas into monovalent copper into divalent copper, and the generation of chlorine gas in the anode area is avoided. For example, CN201710258832.7, CN201710213596.7, CN201520196918.8, CN 201420812. x, CN201420194913.7, cn201710030250.3cn201720049603.x, cn20146089.8cn10646322.2, cn108577.6cn201210304555.cn201304304210554.1cn201304304304304524.0cn201304391.7, cn2103042103042103043.7, cn210201210393174. x, CN201110184362.7 of toyowa sea environmental protection equipment ltd, CN 6757, CN201920318863.1, similar anode solution for similar anode solution, CN201920318863.1, CN201210135391.9, CN201110130675.4, CN201920318863.1, etc. are mentioned. The online electrolytic copper extraction method can effectively avoid the generation of chlorine in the anode region, because the ORP of the production line etching solution is about 530-550mV, the formula 1 shows that Cu < + > -e < + > -Cu 2 < + > -519 mV, when the oxidation-reduction potential is 519mV, all monovalent copper is converted into divalent copper, and when the ORP is more than 520mV, monovalent copper ions can not be provided for the anode of the electrolysis equipment, and a large amount of chlorine is still generated at the anode of the electrolysis equipment. If ORP value parameters of the etching production line are lower than 519mV in order to ensure that certain monovalent copper ions exist in the etching solution, the etching production speed of the etching production line is influenced by parameter setting, and the etching quality precision cannot be ensured. Therefore, the method cannot realize stable etching speed and quality, complete copper extraction and recycling of the acid etching solution and avoidance of chlorine generation.

Some other types of copper-containing acidic etching solutions are also mentioned in the patent, such as patent zhuhai special general high-definition chemical company, cn201811091808.x an organic acid etching solution and a use method thereof in circuit board manufacturing, wherein the organic acid is formic acid, acetic acid and the like; the weather glow CN201710896897.4 is an acidic etching solution additive and an acidic etching solution, wherein the additive comprises 1-200 parts by mass of a nonionic surfactant and 1-200 parts by mass of a stabilizer, and the stabilizer is at least one of sulfur-containing urea, thiol and bromide; the acidic etching solution comprises an etching solution base solution and the additive is at least one of a nonionic surfactant polyethylene glycol, polyvinyl ether and polyoxyethylene ether; chilean chemical company, Inc., of Zhuhai city CN201711035468.4CN201310557796.6 introduces an acidic etching solution comprising organic acid, ammonium salt and surfactant; an acidic etching solution and a preparation method thereof, CN201711095558.2 of Huaxi chemical Limited company in Foshan City, the acidic etching solution comprises the following components: sodium chlorate, refined salt, ammonium chloride, hydrochloric acid and additives; wherein: the additive is urea; CN201610767279.5 of Guangdong Chengde electronic science and technology corporation introduces an electrolytic regeneration and recovery method of acidic etching solution containing 5070 g/L of blue vitriol and 10-11% of sulfuric acid; the invention discloses an additive formula of an acidic etching solution copper extraction system, which is characterized in that: the composition comprises the following components in percentage by weight: 15-25% of etching mother liquor, 12-22% of hydrochloric acid, 6-12% of sodium hypochlorite, 2-10% of accelerator, 1-5% of stabilizer and the balance of water; CN201410182018.8 kinds of acidic etching solution recycled by high-density interconnected circuit boards of Tianjin Prin Circuit GmbH, and the components in the acidic etching solution comprise sodium chlorate, potassium chloride, potassium carbonate and the like; the multi-component additive for electrolysis of the acid etching solution, CN201410309155.3 environmental protection science and technology Limited company of Xinruisi in Shenzhen city, comprises the following components in parts by mass: 1-3% of a brightener and a leveling agent; 5-10% of a surfactant; the solvent is 87-96%, and the density and the flatness of the extracted copper are improved; CN201410269509.6 of Changsha Mutelai Circuit technology Limited is an acidic etching solution for PCB, which comprises the following components in percentage by weight: etching mother liquid copper 130-180g/L, hydrochloric acid 120-200g/L (the concentration of hydrochloric acid is 30-38%), oxidizing agent 150-250g/L, industrial salt 120-250g/L, stabilizing agent 0.5-15g/L, accelerating agent 5-30g/L, buffering agent 0.05-0.2g/L, and the balance of water; CN201410181502.9 etching solution and the use of the etching solution, 130-doped copper chloride dihydrate, 250 g/L; 30% hydrochloric acid, 100-; 26.7-128.4g/L of ammonium chloride; 0.5-16g/L of bank protection agent; auxiliary solvent, 2-6 g/L; an acid etching solution, a preparation method and an application thereof, CN201210039679.6 of Shanghai Zhengfan science and technology Limited company, comprise the following components: 1-20 wt% of hydrofluoric acid, 20-60 wt% of nitric acid, 1-20 wt% of fluosilicic acid and the balance of water. The preparation method comprises the following steps: mixing hydrogen fluoride gas or hydrogen fluoride acid, 70-98 wt% nitric acid water solution and silicon or silicon dioxide serving as raw materials according to the proportion to obtain an acidic etching solution; waiting for glow; the catalyst is ammonia, ethylenediamine, EDTA, triethanolamine and other organic matter as complexing agent to complex monovalent and divalent copper ions, so as to reach the aim of stabilizing etching speed of the etching solution and avoid the problem of generating chlorine gas by using oxidant or electrolytic regeneration. CN200910193746.8, a single-liquid acidic etching solution for forming circuit on printed circuit board by chemical method. The components and the content are 38 to 42 percent of hydrochloric acid, 10 to 12 percent of ammonium chloride, 0.15 to 0.25 percent of additive and 47 to 50 percent of water, wherein the additive is organic matter and other surfactants; trades of rice-flour industries; an oxalic acid type etching solution is introduced by changxi CMS technologies CN 200510080937.5.

Disclosure of Invention

An object of the present invention is to provide an acidic etching solution, an apparatus and a method for recycling copper by electrolytic extraction thereof, and to provide at least the advantages which will be described later.

The invention also aims to provide the acid etching solution, the device and the method for recycling the electrolytic copper extraction of the acid etching solution, which have excellent etching stability, etching speed and fineness, have a simple and controllable in-situ electrolysis recycling mode, obtain a smooth and bright copper plate, have no expansion of the etching solution, generate no chlorine gas, do not need a preparation cylinder to carry out manual intervention and adjustment, and can directly etch back the etching line of the etching machine by the recycling solution.

The technical scheme of the invention is as follows:

an acidic etching solution, which takes water as a solvent, and comprises the following solutes in concentration:

140-160g/L divalent copper, 5-15g/L trivalent ferric ion, 5-10g/L dimethylferrous ion, 1.0-3.0mol/L H +, 230-330g/L chloride ion, 1-10g/L allylthiourea.

A device for recycling electrolytic copper extraction of acidic etching solution comprises:

the etching machine is used for etching the copper-clad plate by adopting an acidic etching solution to form a circuit board, the acidic etching solution takes water as a solvent, and various solutes and the concentrations thereof are 160g/L divalent copper, 5-15g/L ferric ion, 5-10g/L ferrous dimethyl ion, 1.0-3.0mol/L H +, 230-330g/L chloride ion and 1-10g/L allyl thiourea, and the etching machine is provided with an acidic etching solution inlet and a waste liquid storage barrel for storing the etched acidic etching waste liquid;

the electrolytic bath is internally provided with a partition board which divides the electrolytic bath into an anode area and a cathode area, the anode area is provided with a first acidic etching solution waste inlet, a copper-extracted catholyte inlet and an acidic etching electrolyte outlet, the first acidic etching solution waste inlet is connected with the etching machine through a circulating pump, the acidic etching electrolyte outlet is connected with the acidic etching solution inlet, the cathode area is internally filled with catholyte, a catholyte solvent is water, solutes and the concentrations thereof are respectively 10-30g/L monovalent copper ions, 10-30g/L divalent iron ions, 1.0-3.0mol/L H +, 230-330g/L chloride ions, the cathode area is provided with a second acidic etching waste liquid inlet and a copper-extracted catholyte outlet, and an acidic etching waste liquid replenishing pump is arranged between the second acidic etching waste liquid inlet and the waste liquid storage barrel, a copper-extraction catholyte supplementary pump is arranged between the copper-extraction catholyte outlet and the copper-extraction catholyte inlet;

the first specific gravity sensor is used for detecting the specific gravity value of the current acidic etching solution, the copper-extracted catholyte supplementary pump is electrically connected with the first specific gravity sensor, and the copper-extracted catholyte supplementary pump is started when the specific gravity value of the current acidic etching solution is higher than a first set value;

the second specific gravity sensor is arranged in the cathode region and is used for detecting the specific gravity value of the catholyte in the current cathode region, the second specific gravity sensor is electrically connected with the acidic etching waste liquid replenishing pump, and the acidic etching waste liquid replenishing pump is started when the specific gravity value of the catholyte in the current cathode region is lower than a second set value;

an oxidation-reduction potential sensor which is arranged in the anode area and detects the ORP value of the current acidic etching solution;

an electrolytic rectifier inserted into the electrolytic cell and electrically connected to the oxidation-reduction potential sensor, wherein the electrolytic rectifier adjusts an electrolytic current when an ORP value of the current acidic etching solution is higher than a set ORP value;

an ampere-hour sensor disposed on the electrolytic rectifier;

and the allyl thiourea supply metering pump is electrically connected with the ampere hour sensor and is started at regular time.

Preferably, in the device for recycling the copper extracted by the acid etching solution through electrolysis, the ORP value is set to be 600-650 mV.

Preferably, the device for recycling copper in the electrolytic copper extraction of acidic etching solution further comprises a chlorine sensor, wherein the chlorine sensor detects the current chlorine concentration value in the anode region and is electrically connected with the electrolytic rectifier, and the electrolytic rectifier is turned off when the current chlorine concentration value reaches an alarm threshold value.

Preferably, in the device for recycling the electrolytic copper extraction of the acidic etching solution, the supplement amount of the allylthiourea is 0.1-1g/100 A.h.

A method for recycling electrolytic copper extraction of acidic etching solution comprises the following steps:

etching the copper-clad plate by using an acidic etching solution to form a circuit board and obtain an acidic etching waste solution, wherein the acidic etching solution takes water as a solvent, and various solutes and the concentrations thereof are 160g/L of divalent copper, 5-15g/L of ferric ion, 5-10g/L of ferrous dimethyl ion, 1.0-3.0mol/L H +, 230 g/L of chloride ion and 1-10g/L of allyl thiourea,

one part of the acidic etching waste liquid flows into a waste liquid storage barrel, the other part of the acidic etching waste liquid reaches an anode region of an electrolytic tank through a circulating pump and is electrolyzed together with a cathode liquid of a cathode region to respectively obtain an acidic etching electrolyte, a copper-extracted cathode liquid and a copper plate, and the acidic etching electrolyte returns to an etching machine to be mixed with the acidic etching liquid and then etches the copper-clad plate to complete circulation;

detecting the specific gravity value of the current acidic etching solution, and starting a copper-extracted catholyte replenishing pump when the specific gravity value is higher than a first set value, so as to replenish the copper-extracted catholyte into an anode area;

detecting the specific gravity value of the catholyte in the abandoned cathode region, and starting an acidic etching waste liquid replenishing pump when the specific gravity value is lower than a second set value, so as to replenish the acidic etching waste liquid into the cathode region;

detecting the ORP value of the current acidic etching solution, and adjusting the electrolytic current when the ORP value is higher than a set ORP value, wherein the set ORP value is 600-650 mV;

detecting the current chlorine concentration value in the anode region, and closing the electrolytic rectifier when the current chlorine concentration value reaches an alarm threshold value;

and (3) opening the allyl thiourea supply metering pump at regular time to supply allyl thiourea into the acidic etching waste liquid, wherein the supply amount is 0.1-1g/100 A.h.

The invention has the following beneficial effects:

the acid etching solution is added with the allylthiourea, so that the time production of fine circuits is realized, the line width and line distance of etching precision reaches 50um, and the allylthiourea is automatically supplemented, so that the copper plate obtained by electrolysis has bright, smooth and high density, no copper nodules, effectively prevents the anode and cathode short circuit, reduces the electrode polarization side effect, improves the electrolysis efficiency, and has low heat release. The purity of the copper plate obtained by electrolysis reaches more than 99 percent;

carrying out electrolytic copper extraction by adopting an anionic membrane electrolysis and low current voltage cathode protection method to obtain a flat and bright copper plate;

when the etching machine is stopped or the ORP value of the liquid in the anode area of the copper extraction equipment is higher than the control value of 600-650mV, the working voltage of the rectifier is automatically reduced to 0.337-1.359V, the cathode copper is subjected to cathode protection, the copper electrolyzed is prevented from being corroded by the etching solution, and the chlorine in the anode area is avoided.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a schematic diagram of a fine etching process using an acidic etchant according to the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of the device for recycling copper from the acidic etching solution by electrolysis.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

The invention provides an acidic etching solution, which takes water as a solvent, and comprises the following solutes in concentration:

The copper-containing composite acidic etching solution comprises bivalent copper ions, a small amount of ferric ions, a small amount of bivalent ferrous ions, chloride ions, sodium ions, allylthiourea, hydrochloric acid and water, wherein 140-160g/L bivalent copper, 5-15g/L trivalent iron ions, 5-10g/L bivalent ferrous ions, 1.0-3.0mol/L H + concentration, 230-330g/L chloride ions, 1-10g/L allylthiourea and the balance of water.

The concentration of H + is controlled to be 1.0-3.0mol/L, the specific gravity is 1.320, and the ORP530-550 mV is controlled by the etching production line parameters. The etching speed reaches 35-45um/min, and the line width and line distance of the etching precision reaches 50 um.

The allyl thiourea is a weak corrosion inhibitor and can form a weak copper-allyl thiourea complex layer on the copper surface. As shown in fig. 1, the copper-allylthiourea complex layer on the copper surface 1 can be damaged by the etching solution during the spray etching process without affecting the further etching of the bottom copper. After the copper-allylthiourea complex layer is washed and etched away, the allylthiourea is re-dissolved in the etching solution, and the components are kept inconvenient. With the further progress of etching, the allylthiourea and the copper of the side 2 of the circuit form a copper-allylthiourea complex layer, and because the scouring force of the etching liquid medicine sprayed and etched on the side 2 is small and is not damaged, a side corrosion prevention layer is formed, so that the etching production of fine circuits is realized, and the highest capability can reach the precision etching production of line width and line distance of 25um (the traditional alkaline etching liquid medicine can only reach the line width and line distance etching precision of 75-100 um).

The allyl thiourea is a cyanide-free copper plating additive and brightener, forms a complex layer with an electrolytic copper surface in the etching solution in-situ electrolysis copper extraction process, has the functions of uniform copper surface current distribution and potential difference improvement, enables the copper plate surface obtained by electrolysis to be bright, smooth and high in density, has no copper nodules, effectively prevents negative and positive short circuits, reduces the electrode polarization side effect, improves the electrolysis efficiency, and is low in heat release. The purity of the copper plate obtained by electrolysis reaches more than 99 percent. And (3) automatically supplementing the allylthiourea according to the detected electrolytic current and the operating time of the ampere hour sensor, wherein the supplemented allylthiourea is absorbed to the surface of the copper plate along with the electrolytic process, and the supplementing amount is 0.1-1g/100 A.h.

As shown in fig. 2, the present invention also provides a recycling device for copper extraction by electrolysis of acidic etching solution, comprising:

the etching machine 1 is used for etching the copper-clad plate by adopting an acidic etching solution to form a circuit board, the acidic etching solution takes water as a solvent, various solutes and the concentrations thereof are 140-160g/L divalent copper, 5-15g/L ferric ion, 5-10g/L ferrous dimethyl ion, 1.0-3.0mol/L H +, 230-330g/L chloride ion and 1-10g/L allyl thiourea, and the etching machine 1 is provided with an acidic etching solution inlet and a waste liquid storage barrel 4 for storing the etched acidic etching waste liquid;

the electrolytic cell is characterized in that a partition plate is arranged in the electrolytic cell and divides the electrolytic cell into an anode area 2 and a cathode area 3, the anode area 2 is provided with a first acidic etching solution waste inlet, a copper-extracted catholyte inlet and an acidic etching electrolyte outlet, the first acidic etching solution waste inlet is connected with the etching machine 1 through a circulating pump 5, the acidic etching electrolyte outlet is connected with the acidic etching solution inlet, the cathode area 3 contains catholyte, a catholyte solvent is water, the concentrations of the catholyte solvent are respectively 10-30g/L monovalent copper ions, 10-30g/L divalent iron ions, 1.0-3.0mol/L H + and 230-330g/L chloride ions, the cathode area is provided with a second acidic etching waste liquid inlet and a copper-extracted catholyte outlet, and an acidic etching waste liquid replenishing pump 6 is arranged between the second acidic etching waste liquid inlet and the waste liquid storage barrel 4, a copper-extraction catholyte supplementary pump 7 is arranged between the copper-extraction catholyte outlet and the copper-extraction catholyte inlet;

the first specific gravity sensor 8 is used for detecting the specific gravity value of the current acidic etching solution, the copper-extracted catholyte supplementary pump 7 is electrically connected with the first specific gravity sensor 8, and the copper-extracted catholyte supplementary pump 8 is started when the specific gravity value of the current acidic etching solution is higher than a first set value;

a second specific gravity sensor 9 disposed in the cathode region 3 and detecting a specific gravity value of the catholyte in the current cathode region, wherein the second specific gravity sensor 9 is electrically connected to the acidic etching waste liquid replenishing pump 6, and the acidic etching waste liquid replenishing pump 6 is turned on when the specific gravity value of the catholyte in the current cathode region is lower than a second set value;

an oxidation-reduction potential sensor 10 which is arranged in the anode region 2 and detects the ORP value of the current acidic etching solution;

an electrolytic rectifier 11 inserted into the electrolytic cell and electrically connected to the oxidation-reduction potential sensor 10, wherein the electrolytic rectifier 11 adjusts an electrolytic current when an ORP value of the current acidic etching solution is higher than a set ORP value;

an ampere-hour sensor provided on the electrolytic rectifier 11;

In an embodiment of the recycling device for copper electrowinning from acidic etching solution provided by the present invention, the ORP value is set to 600-650 mV.

In an embodiment of the device for recycling copper in the electrolytic extraction of acidic etching solution provided by the present invention, the device further comprises a chlorine sensor, which detects a current chlorine concentration value in the anode region and is electrically connected to the electrolytic rectifier, and the electrolytic rectifier is turned off when the current chlorine concentration value reaches an alarm threshold.

In one embodiment of the device for recycling the copper extracted by the electrolysis of the acidic etching solution, the supplementary amount of the allylthiourea is 0.1-1g/100 A.h.

The acid etching solution adopts an anion membrane electrolysis and low current voltage cathodic protection method to carry out electrolytic copper extraction, the normal electrolytic voltage is 1.5-2V at ordinary times, and the current is 500-800A; the anode area is controlled by ORP oxidation-reduction potential, and the control value is 650mV higher than the ORP control parameter 530 of 550mV of the circuit board etching production line. A chlorine alarm is arranged in the anode area and linked with the protection of the electrolytic rectifier, and the power supply of the rectifier is automatically cut off when the chlorine is detected. The current and the running time of the electrolytic rectifier are detected by an ampere-hour sensor, and the allylthiourea is automatically added by a metering pump. When the working solution in the anode region reaches the control value of 600-650mV, the etching line is recycled. When the etching machine is stopped or the ORP value of the liquid in the anode area of the copper extraction equipment is higher than the control value of 600-650mV, the working voltage of the rectifier is automatically reduced to 0.337-1.359V, such as 1V, and the current is 10-200A, so that the cathode copper is subjected to cathode protection, the electrolyzed copper is prevented from being corroded by the etching solution, and the chlorine in the anode area is avoided.

Slave formula 3Fe²⁺-e＝Fe³⁺Phi 771mv shows that ORP is free of ferrous iron until reaching 771mv or more. The ORP set value of the anode liquid of the electrolytic cell is 600-650 which is higher than the ORP set value of the etching production line 530-550mv and lower than the standard oxidation-reduction potential of ferrous iron, thereby ensuring that the reaction of the anode area in the process of electrolytic copper extraction is the formula 1Cu⁺-e＝Cu²⁺Phi 519mv and partial formula 3Fe²⁺-e＝Fe³⁺Phi 771mv, not being of the formula 22 Cl^--2e＝Cl₂Phi is 1359mv, thus eliminating the generation of chlorine gas in the anode area of the electrolytic cell.

The parameters of the working solution in the anode area of the electrolytic copper extraction equipment are the same as the parameters of the acid etching solution of the etching line, wherein 140-160g/L of divalent copper, 5-15g/L of ferric ion, 5-10g/L of divalent ferrous ion and 1.0-3.0mol/L H⁺Concentration, 230-. 10-30g/L monovalent copper ion, 10-30g/L divalent iron ion, 1.0-3.0mol/L H + concentration, 230-330g/L chloride ion and the balance of water. And (3) detecting the specific gravity of the anode area on line, when the specific gravity is increased to be more than 1.320, filling the liquid obtained after copper is extracted from the cathode into the anode liquid, oxidizing the monovalent copper and the divalent iron into the divalent copper and the trivalent iron in the anode area, and then circularly etching back the production line for use, wherein the ORP reaches 600-650mv as a detection and recycling standard.

The reaction process and principle of the acid etching solution etching production are as follows: cu²⁺+Cu＝2Cu⁺；Fe³⁺+Cu＝Fe²⁺+Cu⁺

The reaction process and principle of cathode copper extraction of the acidic etching solution are as follows: cu²⁺+e＝Cu⁺；Cu⁺+e＝Cu

The anode regeneration reaction process and principle of the acidic etching solution are as follows: cu⁺-e＝Cu²⁺；Fe²⁺-e＝Fe³⁺

The invention also provides a recycling method for electrolytic copper extraction of the acidic etching solution, which comprises the following steps:

etching the copper-clad plate by using an acidic etching solution to form a circuit board and obtain an acidic etching waste solution, wherein the acidic etching solution takes water as a solvent, and the solute concentration of the acidic etching solution is 140-160g/L divalent copper, 5-15g/L ferric ion, 5-10g/L dimethylferrous ion, 1.0-3.0mol/L H mol⁺230-330g/L chloride ion, 1-10g/L allyl thiourea,

Etch line parameter control H⁺The concentration is 1.0-3.0mol/L, the specific gravity is 1.320, and the ORP530-550 mV.

Carrying out electrolytic copper extraction by adopting an anionic membrane electrolysis and low current voltage cathodic protection method, connecting electrolytic copper extraction equipment with an etching machine, and realizing consistency of the concentration of the solution in the anode area of the electrolytic copper extraction machine and the acidic etching solution in the etching machine by adopting a circulating pump, wherein the circulation is uniform, the electrolytic voltage is 1.5-2V, and the current is 500-; the anode area is controlled by ORP oxidation-reduction potential with the control value of 600-650mV

When the etching line is stopped, the voltage of the acid electrolysis copper extraction equipment is reduced to 0.337-1.359V, such as 1V, and the current is 10-200A, so that the cathode copper is subjected to cathodic protection, the electrolyzed copper is prevented from being corroded by the etching solution, and the chlorine generation in the anode area is avoided.

In the continuous electrolysis process, tail liquid after copper extraction in the cathode area is automatically added into the anode area according to the specific gravity rise of working liquid in the anode area, if the specific gravity is set to be 1.320, when the specific gravity is higher than a set value, a cathode liquid replenishing pump is started. The time for replenishing the catholyte by the catholyte replenishing pump can be set to be 0-300 seconds, the time for waiting for one time after the catholyte is replenished can be set to be 0-300 seconds, and the number of replenishing and waiting circulation periods can be set to be 0-1000 times. Through the logic circulation addition control, the anolyte can obtain stable specific gravity, the fluctuation range is less than 0.001, the fluctuation control mode of specific gravity control high-start low-stop is avoided, and etching liquid medicine with stable components is obtained.

When the working liquid of the anode region reaches the control value of 600 minus 650mV and the etching line is recycled, when the working liquid is higher than the control value of 600 minus 650mV, the working voltage and current of the rectifier are automatically reduced to 0.337-1.359V, such as 1V, and the current is 10-200A, so as to carry out cathode protection on cathode copper, prevent the electrolyzed copper from being corroded by the etching liquid, and simultaneously avoid the generation of chlorine gas in the anode region.

The compact bright copper-nodule-free 99% high-purity copper plate is obtained through the processes, and the copper plate is lifted every 3 to 7 days.

The specific implementation case one:

acid etching copper extraction and recycling of a certain circuit board factory in Jiangsu province are carried out, copper-containing compound acid etching solution is adopted for etching production, and an anion membrane electrolysis and low-current voltage cathode protection method is adopted for carrying out electrolysis copper extraction and recycling. 140g/L of divalent copper, 5g/L of ferric ion, 10g/L of divalent ferrous ion, 2.0mol/L H + concentration, 330g/L of chloride ion,5g/L of allyl thiourea and the balance of water. Etch line parameter control H⁺Concentration 2.0mol/L, specific gravity 1.320, ORP535 mV. The etching speed is 5 m/min, the copper etching amount is 5kg/h, the circuit precision of the circuit board is 50um, the current of the electrolytic rectifier is 600A (the working range of the rectifier is 0-1000A), the copper extraction speed is 5kg/h, and the change of copper ions is monitored in real time to adjust the current of the rectifier. After 5 days and 24 hours of etching production and electrolytic cycle regeneration, 630kg of electrolytic copper plate with the purity of 99.1 percent is obtained in total. The comprehensive power consumption is 3500 degrees/ton copper.

The specific implementation case two:

acid etching copper extraction and recycling in a certain circuit board factory in Zhejiang, etching production is carried out by adopting a copper-containing compound acid etching solution, and electrolytic copper extraction recycling is carried out by adopting an anion membrane electrolysis and low-current voltage cathode protection method. 150g/L of bivalent copper, 5g/L of ferric ions, 15g/L of bivalent ferrous ions, 2.5mol/L H + concentration, 300g/L of chloride ions, 3g/L of allylthiourea and the balance of water. Etch line parameter control H⁺Concentration 2.5mol/L, specific gravity 1.330, ORP530 mV. The etching speed of a walking board is 6 m/min, the copper etching amount is 4kg/h, etching production is carried out 12 hours per day, low-voltage low-current cathode protection is adopted at night, the circuit precision of a circuit board is 50um, the current of an electrolytic rectifier is 600A (the working range of the rectifier is 0-1000A), the copper extraction rate is 4kg/h, ORP change is monitored in real time to adjust the current voltage of the rectifier, the voltage is 1V during cathode protection, and the current is 100A. After 10 days and 24 hours of etching production and electrolytic cycle regeneration, 480kg of electrolytic copper plate with the purity of 99.1 percent and the comprehensive power consumption of 4000 degrees/ton of copper is obtained.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. The acidic etching solution is characterized in that water is used as a solvent, and the solute and the concentration thereof are as follows:

140-160g/L bivalent copper, 5-15g/L trivalent ferric ion, 5-10g/L dimethylferrous ion, 1.0-3.0mol/L H +,

230-330g/L chloride ion and 1-10g/L allyl thiourea.

2. Acid etching solution electrolysis copper extraction cyclic utilization device, its characterized in that includes:

an ampere-hour sensor disposed on the electrolytic rectifier;

3. The device for recycling copper in the electrolytic extraction of acidic etching solution as claimed in claim 2, wherein the ORP value is set to 600-650 mV.

4. The apparatus of claim 2, further comprising a chlorine sensor that detects a current chlorine concentration value in the anode region and is electrically connected to the electrolytic rectifier, wherein the electrolytic rectifier is turned off when the current chlorine concentration value reaches an alarm threshold.

5. The device for recycling copper in the electrolytic extraction of acidic etching solution according to claim 2, wherein the addition amount of the allylthiourea is 0.1-1g/100 A.h.

6. The method for recycling the electrolytic copper extraction of the acidic etching solution is characterized by comprising the following steps of: